With tensions between Washington and Moscow soaring over the crisis in Ukraine, top defense officials on both sides have been quietly working on enhancing communications to prevent a sudden or accidental U.S.-Russian military confrontation in the region.

The effort has reached as high as Chairman of the Joint Chiefs of Staff Gen. Martin Dempsey, who has spoken with his Russian counterpart — General Staff of the Armed Forces of Russia Gen. Valery Gerasimov — about reinforcing procedures by which the countries' forces avoid a deadly miscommunication, a senior Pentagon official told The Washington Times.

Air Force Col. Edward Thomas, a spokesman for Gen. Dempsey, confirmed the account and said the officials came to a broad consensus on communication problems last week.

"They did commit to better communication and professional conduct in order to avoid any miscalculation as our forces may encounter each other in common areas," he said.

U.S. and Russian forces have amassed around the conflict area, as instability inside Ukraine continues.

On Tuesday, demonstrators demanding more power for Ukraine's regions stormed the regional administration building in Luhansk, one of the largest cities in Ukraine's troubled east.

About 1,000 demonstrators gathered in front of the building as 150 people, some masked and wielding baseball bats, broke out of the crowd and charged inside, meeting no resistance. Later, protesters formed a corridor to allow police inside the building to leave.

Meanwhile, Ukraine's parliament in Kiev discussed the possibility of holding a national referendum on whether the country should remain united or become a loose federation that allows the regions more powers.

Concerns that the government of Russian President Vladimir Putin is exacerbating the widening destabilization of Ukraine has drawn a U.S. military presence to provide a show of force and contain the crisis. But it has also led to high-profile provocative incidents in which tensions between the countries have flared.

On April 12, one of two Russian warplanes flying in the vicinity of the USS Donald Cook while it was patrolling in the Black Sea buzzed the ship about a dozen times. U.S. military officials contend that the warship tried to communicate with the pilot of the Russian jet, but to no avail.

On April 22, a Russian fighter jet escorted a U.S. RC-135 reconnaissance aircraft as it flew over the Sea of Okhotsk, according to ITAR-TASS News Agency.

Pentagon officials are wary that such incidents have the potential to cause accidents or misunderstandings between the two world powers as they sit on the cusp of an international dispute, a second Pentagon official said. The U.S. military will, from time to time, come into contact with Russian forces, either in international waters or international airspace, the official said.

Although an understanding already exists for what professional conduct entails during international encounters, clearly that conduct needs to be refined, the official said. No new training will occur. Instead, the countries will strive harder to work on their communication problems, according to the official.

"What we want to ensure is the use of protocols, solid communication and professional conduct," the official said.

Efforts to reaffirm and further clarify existing U.S.-Russia accords might prove useful in addressing "indirect dangers," but they will do little to resolve the tension between the two countries, according to Michael O'Hanlon, a senior Brookings Institution fellow specializing in national security and foreign policy issues.

"It won't prevent further escalation between Russia and Ukraine — only Putin's separate decisions can achieve that outcome," Mr. O'Hanlon said. "But it will help prevent inadvertence or accident or a local commander operating on his own from stoking or causing a crisis that top leadership in Washington and Moscow have no desire for."

U.S.-Russia efforts to improve communication come during an auspicious time, when Russian forces and NATO allies are flexing their military muscles near Russia's border with Ukraine.

Ongoing dialogue between the military leaders is important because that is what keeps destabilizing incidents at bay, Col. Thomas said.

"Gen. Dempsey believes that being able to have transparent and candid conversations with his counterpart is vitally important," he said.

Defense Secretary Chuck Hagel has also maintained an ongoing conversation with his Russian counterpart.

Mr. Hagel repeatedly called for a de-escalation of the situation between Russia and Ukraine and recently reiterated that message when talking to Russian Defense Minister Sergei Shoigu on Monday, Pentagon spokesman Rear Adm. John Kirby said.

After that conversation, Pentagon officials issued a statement that implied Mr. Hagel had the upper hand during his dialogue with Mr. Shoigu. Mr. Hagel, the statement said, sought clarification on Russia's intentions toward eastern Ukraine and called for an end to Russia's "continued aggression."

Russian media, however, has portrayed the conversation as somewhat contentious. During the discussion, Mr. Shoigu asked Mr. Hagel to "turn down the rhetoric" over the Ukraine crisis, according to the Moscow Times.

Adm. Kirby told reporters Tuesday that the dialogue between the officials remained civil, even though it was occasionally "terse." Both men, he said, agreed to continue discussing the crisis.